Attorney General Eric Holder announced earlier this week that the federal government will stop raiding medical marijuana dispensaries in states where the plant is legal. The move essentially makes pot legal in, I believe, thirteen states that have passed medical marijuana laws.
Unlike cigarettes and other tobacco products, marijuana isn't lethal and, in fact, has been proven to relieve pain and depression (among other ailments).
Eventually, it will be legal in all 50 states. And a regulated pot industry would be a jackpot of tax revenue for state governments (and the feds, too). In fact, if it were possible to legalize and collect taxes on it today, I bet the revenue would pay for the stimulus package that was passed last month by years end.